The current invention relates to a lock for doors or operationally similar structures, in which the mechanism is manually actuated with the aid of pneumatic means.
The application of pneumatic methods in locking mechanisms is known chiefly for the turning or sliding of the door itself, such as presented for instance in U.S. Pat. No. 4,901,474. Solutions for the actuation of the moving parts of a lock only, using the application of compressed air, have also been suggested. Common to all these solutions is that the locking mechanisms require the importation of external energy.
In U.S. Pat. No. 4,021,066 a pneumatic door bolting system for lorries or railway wagons is proposed; in these vehicles compressed air is as a rule immediately available for braking. The lock proposed in U.S. Pat. No. 4,169,616 requires an air pressure line to the lock from an external source, with which an expensive transmission part from the fixed door frame to the moving door is provided. This applies similarly for the locking system proposed in U.S. Pat. No. 4,691,948. The solutions quoted are based on the supply of external energy, because the manually achievable short-term pneumatic energy is small and is not sufficient to overcome the substantial friction forces, which arise in the opening of conventional door locks.